Air sealing and insulating attic roof trusses – GreenBuildingAdvisor

I’m currently in the planning stage for my new house, climate zone 6a.  I would like to use attic trusses to add additional conditioned space to the house since the site does not allow for a basement. The truss design is attached below. I plan on site building a 1.5” ventilation channel from eve to ridge. Then blowing in dense pack cellulose roughly 16.5” thick parallel to the roof line. Site built supports for insulation netting will be built to allow for this. I’m wondering is drywall on the ceilings below the trusses and on the walls and ceilings of the attic space enough of an air barrier? I’m leaning towards installing intello plus and then a service cavity before drywall on the aforementioned areas to minimize penetrations in the intello. Does T+G subfloor provide adequate air sealing in the attic or would the vapor barrier need to be installed before that as well.

Any advice and thoughts appreciated.